I'm forking this project from http://www.jstott.me.uk/phpcoord/ after a period of development inactivity and being unsuccessful in contacting the original developer. There's an important fix to be made and a small improvement I'd like to add. Unless you've been instructed to use this library, I'd suggest you use a different fork of the same project at https://github.com/dvdoug/PHPCoord. His code is thoroughly modernised and the fix to toSixFigureString() has been been ported to his code.